If I were a dev, I'd probably prioritize that awful 'THIS HAS FAILED!' error when you search for a new community that your server doesn't know about because well, new users who don't know that doesn't mean what it says are going to walk away thinking something either doesn't exist or is broken.

I also kinda think that community lists and activity stats should somehow be federated between all the servers that know each other.

Like, lemmy.world knows uncomfortable.business exists, so both servers should know the full list of non-private communities that COULD in theory be federated and be pre-populated in the search results.

And then feddit.org is federated with lemmy.world, so all 3 of the servers should be fully aware of each other's communities so that a user that lands on ANY instance immediately has a working searchable list of all communities that exist.

Some overhead, sure, but the amount of data here is probably just a one-time big sync and then a small number of updates which is certainly not going to break anything given how chatty lemmy already is.